#include <iostream>
using namespace std;

//Will return the index of the element if found
//else will return -1 .
int binarySearch(const int arr1[], int numElems, int value)
 {
   int leftIndex = 0 ;
   int rightIndex = numElems - 1 ;
   int result = -1 ;
   int middleIndex = 0 ;
   while( leftIndex <= rightIndex )
    {
       middleIndex = ( leftIndex + rightIndex ) / 2 ;
       if ( arr1[middleIndex] == value )
         return middleIndex ;
       else if  ( arr1[middleIndex] < value )
         {
			 leftIndex = middleIndex + 1 ;
		 }
	   else
	     {
			 rightIndex = middleIndex - 1 ;
		 }
	} //while

    return result ;
 }

int main()
{
	int  arr1[] = { 1, 2,  3, 5,  7  }  ;
    cout << binarySearch( arr1 , 5 , 3 ) << endl ;
    cout << binarySearch( arr1 , 5 , 8 ) << endl ;
}